This new radio leads to interesting suggestions (artists I know and artists I never heard):

It's based on a really simple algorithm: we start from a given track, a and grab all the tracks that people played *after* this one. Then we pick a random track among those (with higher weight for more popular tracks).

Rinse and repeat.

The whole thing took less than 100 lines of code to write (tests included) and works suprising well!